Gate valves are well known in the art and have the advantage of providing an unobstructed flow path. In certain gate valves, the valve seat arrangement includes a groove formed between two seat members and, in the closed position of the valve, the gate sits in the groove and seals against the seat members.
Turbulence can be induced in the fluid flowing through the valve by changes in the radius of the waterway. Changes in the radius can be caused by the build up of solid material in the groove between the seats.